I set up a local WP install on my Mac using MAMP to test an issue I've been having (see here for details on that issue if interested: http://wordpress.org/support/topic/cannot-edit-in-visual-mode). My goal is to see if there are any problems with my WP database causing that issue (I have already done a fresh install of WP, disabled all plugins, etc.).
Here's the problem: After importing my database, I could no longer access my local site via http://localhost:8888 (whereas before, I could access the default "Just another wordpress site" and login at http://localhost:8888/wp-admin). Even when I changed the site address in the wp_options table (correctly, because I made note of it when I first installed WP locally), it could not find the local host. So, I did another backup of my live database, excluding the wp_options table, and imported it into my local database. I can access my local site, now with all the posts and pages from my live site, but with the default theme.
HOWEVER, when I try to login using http://localhost:8888/wp-admin, it redirects to my live site's login page. The wp_options table in the local database still says "http://localhost:8888" and I'm NOT redirected when I simply visit the local site. I searched my local database and cannot find anything that relates to my live site's address. I DO NOT have any redirect plugins. And I did restart the MAMP server after making changes to see if that would help.
To export (backup) my database, I used the following instructions, with the exception of excluding the wp_options table: http://codex.wordpress.org/Backing_Up_Your_Database
To move my database, I followed these instructions as best as I could (I cannot login to the local version of WP, since it redirects me to the live login page, and I am not moving any files since I'm trying to test the database): http://codex.wordpress.org/Moving_WordPress
If it helps, my site is http://www.BenjerMcVeigh.com